PSI - Issue 18

Vedernikova A. et al. / Procedia Structural Integrity 18 (2019) 639–644 Author name / Structural Integrity Procedia 00 (2019) 000–000

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specimen surface). The values of heat transfer coefficient for investigated materials were calculated according to the formulas presented in paper Bonacina et al. (1992). It was shown that for specimens from titanium alloys the conduction is the dominating heat transfer mechanism (Fig. 3a). The analysis the evolution of stored energy according equation (6) presented in Fig. 3b coincides with the result obtained by equation (4). This fact confirms the adequacy of the assessment of dissipated energy and efficiency of using the stored energy value as a parameter fracture diagnosis. (a) (b)

Fig. 3. (a) The different contributions of conduction, convection and radiation to the total energy dissipation; (b) Time dependence of heat dissipation and stored energy for Grade 2 (Eq. 6). 4. Conclusion Some aspects related to thermal and energy responses associated with titanium alloys specimens subjected to tensile tests were investigated in this work. Dissipated and stored energy estimation in deformed metals was performed based on post-processing of infrared thermography data. It was shown that the predominant heat transfer mechanism for titanium alloys is conduction. When the value of stored energy reaches a critical value that means materials prepared to the failure. The stored energy is a thermodynamic parameter, which can be used for damage evolution assessment. Acknowledgements The reported study was funded by RFBR according to the research project №18-31-00293. References Rosakis, P., Rosakis, A.J., Ravichandran, G., Hodowany J., 2000. A thermodynamic internal variable model for the partition of plastic work into heat and stored energy in metals. J. Mech. Phys. Solids 48, 581-607. La Rosa, G., Risitano, A., 2000. Thermographic methodology for rapid determination of the fatigue limit of materials and mechanical components. Int. J. Fatigue 22, 65–73. Oliferuk, W., Maj, M., Raniecki B., 2004. Experimental analysis of energy storage rate components during tensile deformation of polycrystals. Mater. Sci. Eng. 374, 77-81. Benaarbiaa, A., Chrysochoos, A., Gilles R., 2014. Kinetics of stored and dissipated energies associated with cyclic loadings of dry polyamide 6.6 specimens. Polymer Testing 34, 155-167. Risitano A., Risitano G., 2010. Cumulative damage evaluation of steel using infrared thermography. Theor. Appl. Fract. Mec. 54(2), 82-90. Plekhov, O.A., Saintier, N., Naimark, О.B., 2007. Experimental study of energy accumulation and dissipation in iron in an elastic-plastic transition. Tech. Phys. Lett. 52(9), 1236-1238. Fedorova, A., Bannikov, M., Terekhina, A., Plekhov, O., 2014. Heat dissipation energy under fatigue based on infrared data processing. Quant Infrared Thermogr J. 11(1), 2-9. Iziumova, A.Yu.,Vshivkov, A.N., Prokhorov, A.E., Plekhov, O.A., Venkatraman, B., 2016. Study of heat source evolution during elastic-plastic deformation of titanium alloy Ti-0.8Al-0.8Mn based on contact and non-contact measurements. PNRPU Mechanics Bulletin 1, 68–81.